Organizations face malware-related events that bypass traditional defense technologies on their networks every three minutes, according to a new report released Wednesday by security vendor FireEye.

"This activity can include the receipt of a malicious email, a user clicking a link on an infected website, or an infected machine making a callback to a command and control server," the company said in its report.

The conclusion is based on data gathered during the second half of 2012 by several thousand FireEye security appliances installed on corporate networks around the world, the company said. These appliances are normally deployed behind network firewalls, intrusion prevention systems and other gateway security products, allowing them to see malicious activity that successfully bypassed those primary defenses, FireEye said.

Malware writers are increasingly focusing on developing methods to evade detection, the FireEye researchers said in the report. One example is malware that lies dormant until it detects human interaction with the target system through the presence of mouse clicks.

This method is used to bypass automated analysis systems, known as sandboxes, which are used by security products to safely execute and analyze the behavior of suspicious files. Since they're automated, these systems do not trigger mouse commands, the FireEye researchers said.

Another growing trend is that of malware files that are signed with stolen or forged digital certificates. Many security technologies trust digitally signed files and don't scan them, the FireEye researchers said.

The creators of advanced malware -- so-called advanced persistent threats (APTs) -- are increasingly distributing their malicious payloads as dynamic link libraries (DLLs) that can be sideloaded via legitimate programs. This is an attempt to bypass traditional defense mechanisms that focus on detecting and analyzing .exe files.

APTs are mostly distributed through spear-phishing emails that carry malicious attachments or include links to exploit-serving websites. Malicious attachments and Web-based exploits are used as infection methods on a regular basis, but certain events can lead to spikes in their usage.

For example, if a new exploit for Adobe Reader is found, organizations will see a spike in emails carrying malicious PDF attachments. Similarly, if a browser-based exploit is discovered, there will be a spike in emails carrying malicious links, FireEye said.

The data analyzed by FireEye, which covers 89 million malicious events, showed that technology companies are the most frequently attacked organizations. "Due to a high concentration of intellectual property, technology firms are hit with an intense barrage of malware campaigns, nearly double compared to the next closest vertical," the company said. The telecommunications, logistics and transportation, manufacturing and financial services sectors complete the top five most targeted verticals.